The invention relates to a crane hook apparatus, and more particularly, to such apparatus which permits a remote control of the engagement and disengagement of a hook with or from a load.
In the description to follow, containers, machines or suspension frameworks adapted to engage a hook apparatus of a crane will be inclusively referred to as "loads", and members thereon having openings or muzzles such as hooks, slings, bails, beams or the like will be inclusively referred to as "catches". The term "hook" or "hook apparatus" is intended herein to refer to an element or an apparatus associated with a crane and adapted for engagement with or disengagement from a catch on a load.
In the construction of conventional cranes, a crane driver does not participate in the operation of engaging or disengaging a hook from a catch on a load since he is located in a driver's cab which is at a distance from the location of the load. A hook is usually associated with a locking device which is designed to prevent an unintended fall of the load as it is being conveyed, and which is normally spring biased into it operative position in which it closes the opening of a recess in the hook. The locking device engages a stop which inhibits its movement toward the outside of the recess from the operative position, and therefore the locking device has to be retracted into its inoperative position inward of the recess before the hook can be engaged with or disengaged from a catch on a load. As a consequence, the known arrangement required the presence of operating personnel at the location where a load is being loaded or unloaded in order to perform the operation of engaging or disengaging the hook.